CA1117197A - Electrical connector including insulation-opening contact - Google Patents
Electrical connector including insulation-opening contactInfo
- Publication number
- CA1117197A CA1117197A CA000259357A CA259357A CA1117197A CA 1117197 A CA1117197 A CA 1117197A CA 000259357 A CA000259357 A CA 000259357A CA 259357 A CA259357 A CA 259357A CA 1117197 A CA1117197 A CA 1117197A
- Authority
- CA
- Canada
- Prior art keywords
- conductor
- contact
- sidewall
- insulation
- contact according
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
- H01R4/00—Electrically-conductive connections between two or more conductive members in direct contact, i.e. touching one another; Means for effecting or maintaining such contact; Electrically-conductive connections having two or more spaced connecting locations for conductors and using contact members penetrating insulation
- H01R4/24—Connections using contact members penetrating or cutting insulation or cable strands
- H01R4/2416—Connections using contact members penetrating or cutting insulation or cable strands the contact members having insulation-cutting edges, e.g. of tuning fork type
- H01R4/2445—Connections using contact members penetrating or cutting insulation or cable strands the contact members having insulation-cutting edges, e.g. of tuning fork type the contact members having additional means acting on the insulation or the wire, e.g. additional insulation penetrating means, strain relief means or wire cutting knives
- H01R4/2466—Connections using contact members penetrating or cutting insulation or cable strands the contact members having insulation-cutting edges, e.g. of tuning fork type the contact members having additional means acting on the insulation or the wire, e.g. additional insulation penetrating means, strain relief means or wire cutting knives the contact members having a channel-shaped part, the opposite sidewalls of which comprise insulation-cutting means
Landscapes
- Multi-Conductor Connections (AREA)
- Connector Housings Or Holding Contact Members (AREA)
- Connections By Means Of Piercing Elements, Nuts, Or Screws (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
This invention relates to electrical connector of the insulatlon-piercing type. When dealing with stranded conductors, oftentimes the strands snag upon, and even become severed by, the edges which are provided for piercing the insulation of an insulated conductor. The present invention provides an improved electrical connector provided with a plurality of contacts, each of the contacts having an insulation-opening terminal element of sheet metal construction to electrically contact an insulated conductor. The contact is advan-tageously constructed for receiving an insulated stranded conductor, but is equally applicable for receiving an insulated solid conductor. Each contact includes an active portion, of either male or female configuration, a terminal element portion, and an intermediate portion connecting the active and terminal element portions. The terminal element portion preferably includes an elongate open channel of U-shaped cross-sectional configuration having side and bottom walls, the sidewalls including opposite portions dimpled in to provide inner detents forming, and separated by, a conductor-receiving notch for opening the insulation of the conductor and electrically engaging the underlying exposed con-ductor. A plurality of different embodiments of a detent are offered, each of which advantageously includes an enlarged wiping surface, a notch entrance and a smooth portion adjacent the notch entrance to prevent snagging, and possibly severing, of the individual strands of a stranded conductor.
This invention relates to electrical connector of the insulatlon-piercing type. When dealing with stranded conductors, oftentimes the strands snag upon, and even become severed by, the edges which are provided for piercing the insulation of an insulated conductor. The present invention provides an improved electrical connector provided with a plurality of contacts, each of the contacts having an insulation-opening terminal element of sheet metal construction to electrically contact an insulated conductor. The contact is advan-tageously constructed for receiving an insulated stranded conductor, but is equally applicable for receiving an insulated solid conductor. Each contact includes an active portion, of either male or female configuration, a terminal element portion, and an intermediate portion connecting the active and terminal element portions. The terminal element portion preferably includes an elongate open channel of U-shaped cross-sectional configuration having side and bottom walls, the sidewalls including opposite portions dimpled in to provide inner detents forming, and separated by, a conductor-receiving notch for opening the insulation of the conductor and electrically engaging the underlying exposed con-ductor. A plurality of different embodiments of a detent are offered, each of which advantageously includes an enlarged wiping surface, a notch entrance and a smooth portion adjacent the notch entrance to prevent snagging, and possibly severing, of the individual strands of a stranded conductor.
Description
Thl~ inverltiorl relates to e3.ectrJ.ctll connectors Or the insu].atiorl-pi~rcirl~!; type, and more parkicularly t~ elec-trical connector~ havirlK contactC) which are construct~d to recelve and clectrlcally c:ontact Lnsulated stranded conduc-tors, as w011 as irlsulated solid conductors.
E:lectrl.cal connectors havirlg insulation-plercirlg contac~s are well known ln the art. For example, one may refer to IJnited States I~tte:rs Patent 3,867,oo5, issued February 18, 1975, to Paul Peter Hoppe, ~r., and as~igned to Bun~r Ramo Corporat-lon. Yopp United States Letters Patent 3,002,176 also dlscloses this general type o~ elec-trlcal connector.
Heretofore, electrical connectors have utllized such technlques as crimpin~ and solderlng ~o connect both solid and stranded conductors to the contacts of an elec-trical connector.
As set forth ln the arorementioned patents, the usual techni~ue for connect~ng circuit elements, such as the mentioned conductor~, to the contacts of the connector, has been to str-~p the ~nsulatlon rrom the end of the con-ductor and to solder the conductor ko a contact. This is a very time-consuming operation and the procedure requires cons~derable skill) particularly where miniaturlzed connec-tors are concerned. When using soldering techniques, khere is also the possibility of undesirable bridging connections occurring between adJacent contacts of` the connector due to the tendency of` solder to follow a heated path upon with-drawal o~ a soldering implement.
As also set ~orth in the af`orementioned patents, an alternative technique which has gained increasing ac-ceptance in the art is the utilization of insulation-piercing terminal elements a.s a portion of the contacts.
Such terminal elements sever or cut through the insulat~on ~' . , , ~L17~5~7 and establish all e:L~ctric~l connection to the conductor without strippin~ and without sold~ri~g Insulation-piercing terminal elements usually involve the utilization Or a forked structure having cutting edges that sever and penetrate the insulation, and serve as wiping surfaces in some configurations, to make the neces~
sary electrical, and ~or that matter mechanical, connection with the conductor. The insula-tion-piercing terminal there~ore serves to sever the insulation of the conductor and to act both as a mechanical and electrical connection for the contact and the con-ductor.
The aforementioned art is ~ully acceptable and completelysatisfactory for electrically contacting insulated conductors, particularly the solid insulated conductors. When dealing with stranded conductors, however, particularly stranded conductors in the range of 24-28 gauge, o~tentimes the strands snag upon, and even become severed by, the edges which are provided i'or piercing the insulation of an insulated conductor. When using stranded conductors, undesirable problems can therefore arise due to snag-ging and/or severing of the individual strands, including incom-plete and sometimes noisy connections which are intolerable.
The primary object of the invention, therefore, is to provide an electrical connector having insulation-opening contacts which overcome the aforementioned problems concerning snagging and/or severing of the individual strands of an insulated stranded conductor.
Another object of the invention is to provide an insul-ation-piercing or opening contact for an electrical connector, which contact is suitable for terminating both insulated stranded and insulated solid conductors.
Another object of the invention is to provide an ~ -2-: i ~7 electrical contact ~or an electrical connector in whLcll the termination elemont includes conductor retention mean,s ~or ensuring that a conductor remains seated in a desired position once the conductor has been inserted to that positi~n, A ~urther object is to substitute smooth guide sur~.lcos for at least part of the tapered cutting edges to reduce snnggin~
and/or severing of the strands o~ an insulated stranded conductor, Still another ob~ect is to form the smooth ~uide sur-faces from the smooth flat uncut side o~ sheet metal, 10An additional object is to provide side and bottom support for insulation-piercing detents so that the det~nts ex-hibit suf~icient strength to penetrate or move the insui~tion to expose the underlying conductive strands while provid~ng a smooth surface to guide the strands to a lower wiping surface, According to the invention, there is provided an insu-lation-opening contact of the type wherein an insulated conductor is pressed into a nQtch which opens the insulatlon and provides a wiping contact surface portion for the conductor, compr~ses a thin sheet metal structure forming an open channel ~or receiv~ng an insulated conductor normal to its axis, the channel including a bottom wall and a pair of spaced sidewalls extending ~ener~lly parallel to each other from the bottom wall. At least one pair of separate detent portions extend inwardly of the channel ns opposing inside surfaces of the channel, with eneh detent portioll of the pair being opposite the other and with ench detent portion comprising a continuous and oblique surface and having n roundod change of direction. The oblique surfaee forms an entity witlt ; an upper portion of the vertical walls of each detent nnd is continued by the junction of the vertical walls to ~orm the wiping contact surface, The continuous and obliquo surrac~
contains a guiding surface and an insulation-ope~ sur~nco which fornts a curved transition surface to tho wlpln~ eo)l~aet sur~ace.
.~ -3-Inasmuch ng it is desirnble in the production o~
contacts o~ an electrical connector to provide an el0ctrical connec-tor which is mechanically stable over a long period o~
time, and as a hi~h tensile strength sheet metal has ~ound to be suitable ~or contact use over an extended period, and as certain production problems concernlng ~he bendlng o~ high ten~
sile strength sheet metal material iarise when resiliency over n short length is concerned, particularly with respect to double and reverse bends at the active portion G~ a contact to providc both male and female con~igurations, another obJect o~ the -lnven-tion is to provide an insulation-opening~ contact structure havln~
an act~ve portion connected thereto by a stable coniiguration which avoids sharp reverse bends and which utili~es a material having su~icient resiliency to serve i'or a great number oi' engagement and disengagement operations over an extended period o~ time.
-3a-~ pr:l.rlla.ry fCclt;Ur'e O:L' the .I.nve7~ , rec,ide~ ln the pxovi~sior~ Or ~n l.nsulatioll-openlng notch, preferably in a U-shapecl Ghannel, ~or openlrlr the insulatlon and contacting a concluctor wi-th a w~pirlg action ~he notch lncludes an enlarged conductor wlping sur~ace, a smooth lead-in sur~ace3 and a portion which de~lnes a change of directlon between the lead-in surface and the wiplrlg surface. Advantageously, the notch may be formed by press-forming a pair of ln~ardly dlrected detents which carry the abc)ve mentloned surfaces~
although a variety of other structures and techniques may be utilized dependlng on dlfferen~ constructlon and applica-tion requlrements.
Other objects, features and advantages of the lnven-tion, its organization, construction and operation wlll be best understood from the following detailed description taken in conjunction with the accompanying drawlng, on whlch:
FIG. 1 1~ a fragmentary perspective view ~ ~n electrical connector constructed in accordance with the present invention;
FIG. 2 is an enlarged perspective v-lew ~ a por-tlon of a contact termination element constructed in accordance with khe invention;
FIGS. 3, 4 and 5 are sectional views taken sub-stantially along the line II-II of FIG. 1 illustrating an lnsulated stranded conductor at di~ferent posltions during the insertion process;
FIG. 6 ls a fragmentary sectional and isometric view o~ another embodiment of a termination element con-structed in accordance with the present invention;
FIG. 7 is a fragmentary perspective view o~another embodlment of a termination element constructed in accordance with the invention;
.-,' ~1~7~W7 I~IG. c:3.Ls a i:~r~agmellt~lry sec~J.onal pcrs~ectlve v;lew o~` s~lll arlother em~ocllmt,~rlt o~' a term;lrl~tion elemer-lt con-structed in accordarlce wlth tht? irlve~n);lon;
FIG. 9 is a ~'ragmentary sectional perspectlve vlew ~ stlll another embod~ment ~r a termination element construct~d ln accordance wlth l;he ;invention;
FIG. 10 is a ;eragmentary sectional perspect-lve view of yet another embodiment of a terminatlon element constructed in accordance with the invent-lon;
FIG. 11 ls a sectional view taken su~stantiall~
along khe llne XI-~I o~ FIG. 10;
. 12 i8 a per~pective view o~' another embo~i-~ent o~ a termination element of an electrical contack constructed ln accordance with the prlnclples of the present invention;
FIG. 13 is an enlarged sectional v~ew o~ a conkack terminal element supported between barrier walls o~ a con-nector shown before conductor insertion;
FIG. 1~ is an enlarged seckional view slmilar to FIG. 13, illustratlng the terminal element and conductor a~ter insertion;
FIG. 15 is a fragmentary perspectlve view of the : intermediate and actlve elemenks showlng the folded con-structlon ln greater detall;
FIG. 16 is a sectional perspective view illus-trating a folded end o~ the intermediate element as viewed ln the dlrectlon XVI-XVI ln FIG. 15; and FIG. 17 is a sectionàl view taken along the line XVII-XVII o~ FIG. 16 illustrating the provision o~ support legs.
At the outset, one will appreciate that the appar-atus illustrated in FlG. 1, with the exception of the in-ventive leatures disclosed herein, is substantially khe ;ame con~'.L~ruratlorl o~ I(r. 3 oL' ~he a~or(~ment:l.orle(l U. S.
Patent 3,~67,oo5. It ~.s read:Lly apparerlt ~rom F:~G. 3 of that pa~en~, and ~rom the ln~tant FIG. 1, t'rlat the general constructJ.on of arl electrical connect,or unlt accordin~ to th0 present invention, ls generally the same as disclosed ln FIGS. 1, 2 and 3 o~ U. S. Patenk 3,867,oo5. It ls there-fore readily apparent that the plurality o~ conductors and contacts Or an electrical connector accordlng to the Hoppe patent ls also envisloned for an electrical connector which includes the features of' the present lnventlon.
Referring to FIGS. 1 and 2, the baslc construction of an electrical connector ls lllustrated at 10 as comprls-ing a dlelectric contact mount 12 whlch is lllustrated in the ~orm of a plug unit which is adapted ~or connection to a mating complementary receptacle un-lt (not shown). The plug unit comprises the contact mount 12 which is constructed of` molded dielectric material, such as "DAP" Nylon, or Polyester and is designed to have a pluralit~ o~ spaced barriers 14 which define a plurality o~ contact mounting passages 16. Each o~ the barriers 14 lncludes an extended portion 18 whlch de~ines strain relie~ passages 20. Each of the strain relie~ passages 20 includes an entrance de~in~d by a pair of obllque surfaces 22 and 24.
Each of the contact passages 16 includes a contact 26 mounted therein. Each o~ the contacts 26 includes an active contact element 28, here illustrated as having a hook-shaped reentrant portion 29 as in the aforementioned U. S. Patent 3,867,oo5. The active portion could, however, have any desirable shape. The contact 26 also includes a termination contact element 30 and an intermediate contact element or portion connecting the active and te~mination elements, the intermediate portion to be described in detail below.
I!~aC~I t~-!rm;ln~lt;:lo~ rnerlt comprise; a pa-lr (j~ gen~
~rally parallel slclewa:lls 32 and 34 which extend Konerally perpendiclllclr to a bot-tom wall 36 to f'orm an open ~-shaped configuratiorl .
In the~terminat:Lc)rl contact element 30 illustrated in FIGS. 1 and 2, the s;Ldewal:ls 32 and 34 have been di.mpled to provide inwardly ~irected detents 38 whlch ~ef~-ine a channel constrictlon or notch in whlch the constrlcticJn elements are in an interference relatlonship with at least the insulation Or an insulated conductor to be received -ln the channel. Although the notch i8 illustrated as co~-prising a pair of' opposed inwardly directed detents faclng each o~her, the constrictlon may also comprise a palr of lnwardly directed detents which are of~set longitudinally ~ith respect to each other along the terminatlon contact element.
Eaeh o~ the detents 38 includes a pair of inwardly dlrected portions 40 which respectively ~oin the respectlve sidewall and which ~oin together in an enlarged sur~ace 42 which constitutes a wiping sur~ace ~or an exposed conductor, whether the conductor is solld or stranded. Each detent 38 also comprlses a surface 44 which is continuous w-lth the portions 40 and 42 back to the outer edge of the re-spective sldewall. ~he surface 44 is particularly charac-terized as a smooth surface, at least in the area immedl-ately adjaoent the wiping surface 42 and is further char-acterlzed as developing into the wiplng~surface 42 with a gradual change of direction.
In the construction illustrated in FIG. 2, at least one o~ a plurality of channel walls 32/ 34 and 36 af~ord support against insertlon ~orces ~or the detent.
As illustrated, surface 44 ls supported against insertion ~orces in the direction of insertion by first support m~ r~ r~e~cir~ t(~ / hokl;~)rrl wa ~ ,r.~t~ cl)rlrlec~
-to c1eter1t wal:L l~o. ';lcl~ wa:Ll 32 intel~;rally conrlected to d~t;ent wa~l 40 provlde~ a se~corld ~upport mearls ~'or wiplng surface ll2 agalr1~st i.nsertio~ ~orce~ in a dlrection trans-verse to 1he direction of lnsertion.
A~ lllustrated in ~IGS. 3-5J as an lnsulated con-ductor C is ~orced into the channel~ and thus into at least one notch defined by a pair of detents, the lnsulation I
is opened to expose the conductor SC' so that the same is subJected ~o a wiping contacting o~ the surfaces 4'2. As the lnsulation 1~ forced open as it passes the smooth and gradual change of' direction surfaces~ as opposed to an actual cuttLng type severing, the ind-Lvidual strands, if a stranded conductor is employed, are exposed to the change of direction defined by the surfaces, but the strands are not sub,ected to snagging and/or severing as would be the case wlth contact elements heretofore employed.
Referring agaln to FIG. 2, as a conductor is forced downwardly lnto a termination contact element to a desired posit~on, the conductor passes another detent type element 50 which is embossed and lanced to include an underlying edge 54 which engages the insulation to retain the conduc-tor within the channel.
A number of insertion tools may be employed in terminating electrical conductors in the termination con-tact elements constructed in accordance with the present invention. Another tool which is suitable for utilization with the present invention is illustrated, in part, in FIG. l as comprising an insertion blade 58 havi.ng a plur-ality of insertion portions 60, 62 and 64 which are to bepositioned agalnst a conductor at respectiue locations on each side of an insulation notch. The blade 58 includes narrow portions 66 and 68 which may be ~ormed b~ opposed a:~:lgrled W.l.t:: t;h~e llo i;C~ Lorm~d ~y the deteilt;~ 3~3. ~n ad(lit:i~r~11 tile t~ ncly compr:L~e an .lddit:1Oncll portion (not shown) for ~re~3~:irlg 1;he corlc11lc~or ln~o the stra-l.n rellef ge1lera~:1.y def:1ned by the~ passageway 20.
Because o~ the cles:lrabillty ~o use h:Lgh tenslIe strength materia:lsJ and lnasmuch as such materials lnvolve difEicultie~ in forrning reverse bends and the llke, and as it is highly desirable to use such materlals for ex-tended contact llfe, the present inventlon utllizes aunique contact structure which -ls adaptable eor high ten-sile strength materials and mo1lntlng of` the contacts within a contact mount. This structure comprlses a flap or ex-tension of a portlon of the sldewall 34 which is bent at 90 with respect thereto toward the sidewall 32 and a tab 56 on the sidewall 32 whlch is bent in the opposlte direction to overlie and lock the member 57. This ~orms a stable box-shaped structure at the end o~ the termina-tion contact element which is recelved in a complementary box-shaped portion Or khe passage 16 in the connector mount 12. The member 57 carries the active contact element 28 as a forwardly directed (ln the sense of' connector directions) portions thereof.
In some manufacturing processes, and in the case of different applications, it may be more advisable and ad-vantageous to form the notch defining structures b~ differ-ent processes than the aforementioned detenting process by press-forming the side-walls of the termination contact element, or by press-forming the detents ln a different conflguration. Inasmuch as each of the detents is, in effect, an lnternal wall within the channel, the detents are also hereinafter referred to as inner walls which may have individual wall portions or wall sections.
_g _ ~ r~ (,o ~ t~t ~ , t;ll~ 3~m(~ ~r~no~a~.
sh~e f.`or cl, det,ollt~ :Ia ~ Lust;rLIl;e(il as -1; sh~wn :In Li'I(,TS, 1 ancl 2. In E~ T. ~i, hOWeVeI', eactl o~ det~rlts 78 c om-pr.ises a palr oI~ inwclrd:Iy dixected walls 80 ~lnd ~2 whlch conv~rge in a rounde~ surface B4 cln(l which are ~vined by an obll~ue ~urf'clce ~6 haTIlrlg a smooth port:Lon adJacent the surCace 8LI. The walls and surfaces 80-86 are formed ln a separate process as a cup-sh,lped struc~ure wh:Lch is welded around ttle p~rlphery, as at 88, to the respective sidewall 10 72 which extends from a bottom wa].l 76 parallel to a com-plementary sidewall 74 of a t,ernlination contact element 70.
Referring to FIG. 7~ a termination contact ele-ment 110 is brie.~ly illustrated as comprising a sidewall 112 (the other sldewall not being shown) which extends generally normal to a bottom wall 11~. An inner wall 116 is illustrated as comprising a pair of inwardly directed walls 118 and 120 having a bottom edge 122 above the bottom wall 114 and which are connected by a generally wide wiplng sur~ace wall 124. An additlonal wall 126, characterized by smooth portion ad~acent the surface 124, joins the walls 118, 120 and 124 with the free edge of the sidewall 112.
Referring to FIG. 8, a termination contact element 90 is illustrated as having an lnner wall 96, formed as a detent, including a pair of inwardly directed walls 98 and 100 extending from the sidewall 92 which, in'turn, projects from a bottom wall 94. The contact element 90 may also include another sidewall as in FIGS. 1-5.
A smooth slanted surface 106 ad~acent the surface 104 is carr-led,by a mem~er 108 o~ thin conductive sheet metal which is connected to and bent at an angle with re-spect to the surface 104 with its smooth ma~or surface extending as a cover a~d guide over walls 98 and 100. An aperture 102 has been provided at the junction of the .
G ~ .rl (.~ J r) tJ l~ orn ~ 9l~ ~) f',~ Lt;~ 3 ~'o~rnin~ o~' the c1el,erll; ~y a ~)resslllg process su t;hal, lanc:in~ or an abrupt swedglrl~;; is rlot neces~3al~y at that poirlt;.
~ el~errirlg t~ l?IG. 9) another illustrat,ive embodi-rnent o~ a termlrla~lon con~ac-t element :ls shown at 130 as comprislng at least one sldewall 132 wh-ich pro~ects frorn a bottom wal:L :l36. Of course, a slmllar sidewaLl may ex~
tend from the bottom wall 136 in complementary opposTtion to the sidewall 132. The channel of' the te~lination con-10 tact element includes an lnner wal:L 138 whlch ls formed outof bent substantia].ly 90 f'rom the sidewall 132, the bend-ing being facllitated by an aperture 134 at the junct,ion of the sldewall 132 and the bottom wall 136. The -lnner wall 138 comprises a sidewall portion 140 having an edge 142J
substantlally the thickness of the sldewa:Ll 132 which forms the wiplng surface f'or the conductor. The sidewall portion 140 includes an extended portion 146 which is folded over in a smooth inwardly and downwardly directed fold 144 to define the smooth entrance of the notch~ the junction of the edge surface 142 and the rounded surface 144 deflnlng the change of~ dlrectlon mentloned in respect of the above embodiments.
Referrlng to FIGS. 10 and 11, a terminatlon con-tact element 150 -ls lllustrated as comprlsing a sidewall 152 whlch extends from a bottom wall 154. Again, a complemen-tary opposed sidewall may be provided. 'rhe sidewall 152 has been relieved by an aperture at 164 to facilltate the forming of a dimple ln the production of an inner wall 156 which includes a palr of convergently inwardly directed surfaces 158 and 160 whlch are ~o~ned at a rounded surface 162 which constitutes the conductor wiplng surface. In thls embodiment of the invention the press forming o~ the inner wall occurs more closely adjacent the free edge of 7~7 t~le sl(lewa~ 7,~ Irl F:L(~. ~; sc-, ~ha~; ~he upper edge :l66 of the siclewal:l. 152 is turne(l outwardly and forms a V~shaped notch.
The space hetween ~he V-shaped notch and the Junctlon of`
the suraces 158, 160 and 1~2 therewlth constltutes a smooth surface 168 rOr guldLng the conductor into the notch and preventlng snagg-lng o;~ the individual st~.nds of a stranded conductor as the notch effects opening of thè
insulation. The edges of the V ma~ be colned i~ neces-sar~, to prevent snagging, Referring to FIG. 12, a "channel" without sidewalls is lllustrated, although it is readily apparent that ~ide-walls could be provlded. In FIG. 12, a flat piece of sheet metal is folded three times to form each notch. A "channel"
comprlses a bottom wall 172 hav-lng a palr of notch-de~ining pro~ections extending therefrom, due to the folding process.
Each o~ these pro~ections comprises a pair of coextensive wall sections 17~ and 176 which are ~oined by a rounded, smooth and inwardly obliquely dlrected surface 178. The bottom wall 172 has an aperture therethrough having side-walls 180 which form the wiping surface or surfaces for the exposed conductor.
Re~erring to FIGS. 13 and 14, a more detailed showing of the relationships between the terminal element and the conductor insulation and core are illustrated. As an example) the ~ollowing values are prov-lded ror a clearer understanding of the invention.
D-lameter . ~ . . . . . . . . . . 0.045 Diameter SC. . . . . . . . . . . 0.020 0.015 Notch Width a. O . . . . . . . . 0.009 Channel Inside Width b . . . . . . . . . 0.038 Channel OUtside Width c . . . . . . . . . 0.051 0.049 Barrier-Barrier Distance d . . . . . . . 0.054 ~ rOr11 t;hC d:l!(lell'l;t.OILS ~:';;LV(UI cli~OVC~ Ls appar~rll;
tilat al.l;hOUg,h l;hl' .LiiaU.La~.orL :L3 ~l~)pro~iml~.L;y the sarne d-iamet;~r a~; t;h~ :Lnsttle oL~ the ch~nil~l, th~ conductor d~am~ter i~ much l~lrger tharl the w:klth of the notch. There-for~) as the insula1,ed conductor -l.s pre~ssed into the charl-nel, even assumlng that thc corlductor :ls centered~ a stran-ded core undergoes a cross-sectional di3kortlon due to displacement of the indiVidual strands during insertlon.
This is ll.lustrated in ~'IG. 14. A~sol as pressure is ap-plied to the insulation by an lnsertion tool, the lnsulatlon undergoes dlstortlon and is moved axially of the core and outwardly o~ the channel. It ls dirficult to tell exactly where any individual strand may initlally contact the sur-~ace 44 which leads into the notch. Theref`ore, a smooth surface 44 with a gradual change o~ direcklon to the wip-lng surface is pref`erred to prevent snagglng o~ the indlvidual strands. With larger strands and solld conductors the change of direction can be more abrupt -Ln that the possibility of snagging decreases wlth increasing conductor diameter.
Ref`err~ng again to the dimensions given above, it is readily apparent that any transverse deflection Or the sidewalls 32 and 34 is at a m-lnimum because o~ the dlf~er-ence between the outside channel dimension and the distance between the barriers, for example~ 0.003 inches. The ter-minal element is there~ore well supported and does not open up to any extent to receive the conductor thus insuring good mechanical connect:Lon and good wiping electrical connection.
Rererrlng to FIGS. 15~17, additional details of the box-shaped structure o~ the intermediate element are 3 illustrated. It should be noted that the member 57 includes an embossed detent 184 ~or receiving the tab 56 such that the outer surfaces of the member 57 and the tab 56 are co-planer~ which facilitates insertion of the terminal ends o~
1~7~7 the contacts into the dlelectr:Lc support 12.
One of the slclewalls, the wall 34 ;Ln FIG. 16,also carries a member whlch is folded at 90 toward the opposlte sidewall as ano-ther feature of the box-like structure.
It is sometimes necessary to provide supporting feet for the intermediate element of a cont,act. Refer~-lng to FIG. 17, the bottom wall 36 of the channel may be cuk such as at 186 and 188 to provide a pair of bottom wall sections l90 and 192 which may be folded downwardly to pro-vide supporting feet.
In summary, therefore~ we have dieclosed an in~u-lation-plercing or opening aontact for use in an electrical connector for connection to an insulated conductor, in par-ticular an insulated stranded conductor. The contack, in some embodiments, includes an open channel for receiving the insulated conductor normal to its axis, the channel lnclud-ing a bottom wall and a pair of spaced s~dewalls extending generally parallel to each other from the bottom wall. The channel includes at least one pair of interior walls, ~hich may be constructed of press-formed detents, and which extend inwardly of the channel from respective sidewalls. Each of the interior walls comprises an oblique surface dlrected away from the respeckive sidewall and toward the bottom wall, a conductor wiping surface extending generally in the direction of conductor insertion, and an insulation opening portion joining the oblique and wiping surfaces and defining a change of direction be~ween such surfaces. A smooth portion is providecl on the oblique surface immedlately adja-cent the insulation opening portion advantageously prevents snagging when stranded type conductors are being terminated.
For larger strands, a more abrupt change of direction may be employed; however~ a smooth, gradual change is preferred for conductors in the area of 24-28 gauge.
--1~-St;ate~3 ~.rlother wayJ tt)e lnventl.o~ a ~peclf'l.c lmprovement ror ~lectrical:].y t~ni~a~lrlg an in~ulated stranded corl~uctor, as wcll a3 an insulated solid conduct,or, in an insulated p~ercing contact Or the t~Jpe ln which an lnsulated conductor 1~ pressed normal to its axis into ~n insulated-piercirlg notch wh:Lch has an entrance and a con-ductor wip:lng sur:~ace extendlng transversely of the axls of the conductor. The improvement more speclfically com-prises a smooth ~ur.~ace :immediately adJacent the entrance o~ the notch and extendlng obllque to the notch and a ~unction at the notch enkrance between the smooth surface and the wiplng sur~ace o~ the notch which defines a change of direction between the wiplng surface and the notch entrance, so that, in the case of stranded conductors, exposed strands are not sub~ected to snagging and/or sever-ing by sharp pro~ections or a sharp edge along the guide and lnsulation~opening paths.
Also, according to the invention, an insulation-piercing or -opening contact ~or an electrical connector has been disclosed as comprising a channel for receiving the insulated conductor in a direction normal to its longi-tudinal axis) and notch means in the channel defining a constriction havlng an interference relationship with the insulation of the insulated conductor. The notch means defines conductor guiding, insulation opening and conductor ^-wiping zones and includes a conductor wiping surface which extends generally in the direction of conductor insertion, a conductor guiding surface extending oblique to the wiping surface, and an insulation opening portion connecting and defining a change of direction between the guiding and wiplng surfaces, the guiding surface including a smooth zone immediately adjacent the insulation opening portlon which advantageously serves to prevent snagging of the i.ncl.lvldual ~trarlds of' an :i.nsulated strarlded corlductor.
Accord:in~; ~,o ~;he lnvetlt.l.orl~ an electrical connector unit has also beerl dlsclosed which uti:llzes a plurality o~
contact members rnounted ln ;Lndividual contact mountirlg passages of a con~ack mount of` dielectric materlal. Each of the contact members may advantageously be formed f'rom high tenslle strength sheet metal and comprises an act:Lve contact elementg a terminal contact element and an inter-mediate contact element connecting l;he active and terminal contact elements. The termi~lal element is in the shape of an elongate U-shaped channel w:Lth a box-like structure at its ~unctlon with the intermediate contact element, the intermediate contact element carrying the actlve contact element.
Although we have described our invention by refer-ence to a partLcular illustrative embodiment thereof~ many changes and modifications o~ the invention may become apparent to those skilled in the art without departing from the spirlt and scope of the lnvention. We therefore intend to include within the patent warranted hereon all such changes and modlfications as may reasonably and proper-ly be included within the scope of our contributlon to the art.
E:lectrl.cal connectors havirlg insulation-plercirlg contac~s are well known ln the art. For example, one may refer to IJnited States I~tte:rs Patent 3,867,oo5, issued February 18, 1975, to Paul Peter Hoppe, ~r., and as~igned to Bun~r Ramo Corporat-lon. Yopp United States Letters Patent 3,002,176 also dlscloses this general type o~ elec-trlcal connector.
Heretofore, electrical connectors have utllized such technlques as crimpin~ and solderlng ~o connect both solid and stranded conductors to the contacts of an elec-trical connector.
As set forth ln the arorementioned patents, the usual techni~ue for connect~ng circuit elements, such as the mentioned conductor~, to the contacts of the connector, has been to str-~p the ~nsulatlon rrom the end of the con-ductor and to solder the conductor ko a contact. This is a very time-consuming operation and the procedure requires cons~derable skill) particularly where miniaturlzed connec-tors are concerned. When using soldering techniques, khere is also the possibility of undesirable bridging connections occurring between adJacent contacts of` the connector due to the tendency of` solder to follow a heated path upon with-drawal o~ a soldering implement.
As also set ~orth in the af`orementioned patents, an alternative technique which has gained increasing ac-ceptance in the art is the utilization of insulation-piercing terminal elements a.s a portion of the contacts.
Such terminal elements sever or cut through the insulat~on ~' . , , ~L17~5~7 and establish all e:L~ctric~l connection to the conductor without strippin~ and without sold~ri~g Insulation-piercing terminal elements usually involve the utilization Or a forked structure having cutting edges that sever and penetrate the insulation, and serve as wiping surfaces in some configurations, to make the neces~
sary electrical, and ~or that matter mechanical, connection with the conductor. The insula-tion-piercing terminal there~ore serves to sever the insulation of the conductor and to act both as a mechanical and electrical connection for the contact and the con-ductor.
The aforementioned art is ~ully acceptable and completelysatisfactory for electrically contacting insulated conductors, particularly the solid insulated conductors. When dealing with stranded conductors, however, particularly stranded conductors in the range of 24-28 gauge, o~tentimes the strands snag upon, and even become severed by, the edges which are provided i'or piercing the insulation of an insulated conductor. When using stranded conductors, undesirable problems can therefore arise due to snag-ging and/or severing of the individual strands, including incom-plete and sometimes noisy connections which are intolerable.
The primary object of the invention, therefore, is to provide an electrical connector having insulation-opening contacts which overcome the aforementioned problems concerning snagging and/or severing of the individual strands of an insulated stranded conductor.
Another object of the invention is to provide an insul-ation-piercing or opening contact for an electrical connector, which contact is suitable for terminating both insulated stranded and insulated solid conductors.
Another object of the invention is to provide an ~ -2-: i ~7 electrical contact ~or an electrical connector in whLcll the termination elemont includes conductor retention mean,s ~or ensuring that a conductor remains seated in a desired position once the conductor has been inserted to that positi~n, A ~urther object is to substitute smooth guide sur~.lcos for at least part of the tapered cutting edges to reduce snnggin~
and/or severing of the strands o~ an insulated stranded conductor, Still another ob~ect is to form the smooth ~uide sur-faces from the smooth flat uncut side o~ sheet metal, 10An additional object is to provide side and bottom support for insulation-piercing detents so that the det~nts ex-hibit suf~icient strength to penetrate or move the insui~tion to expose the underlying conductive strands while provid~ng a smooth surface to guide the strands to a lower wiping surface, According to the invention, there is provided an insu-lation-opening contact of the type wherein an insulated conductor is pressed into a nQtch which opens the insulatlon and provides a wiping contact surface portion for the conductor, compr~ses a thin sheet metal structure forming an open channel ~or receiv~ng an insulated conductor normal to its axis, the channel including a bottom wall and a pair of spaced sidewalls extending ~ener~lly parallel to each other from the bottom wall. At least one pair of separate detent portions extend inwardly of the channel ns opposing inside surfaces of the channel, with eneh detent portioll of the pair being opposite the other and with ench detent portion comprising a continuous and oblique surface and having n roundod change of direction. The oblique surfaee forms an entity witlt ; an upper portion of the vertical walls of each detent nnd is continued by the junction of the vertical walls to ~orm the wiping contact surface, The continuous and obliquo surrac~
contains a guiding surface and an insulation-ope~ sur~nco which fornts a curved transition surface to tho wlpln~ eo)l~aet sur~ace.
.~ -3-Inasmuch ng it is desirnble in the production o~
contacts o~ an electrical connector to provide an el0ctrical connec-tor which is mechanically stable over a long period o~
time, and as a hi~h tensile strength sheet metal has ~ound to be suitable ~or contact use over an extended period, and as certain production problems concernlng ~he bendlng o~ high ten~
sile strength sheet metal material iarise when resiliency over n short length is concerned, particularly with respect to double and reverse bends at the active portion G~ a contact to providc both male and female con~igurations, another obJect o~ the -lnven-tion is to provide an insulation-opening~ contact structure havln~
an act~ve portion connected thereto by a stable coniiguration which avoids sharp reverse bends and which utili~es a material having su~icient resiliency to serve i'or a great number oi' engagement and disengagement operations over an extended period o~ time.
-3a-~ pr:l.rlla.ry fCclt;Ur'e O:L' the .I.nve7~ , rec,ide~ ln the pxovi~sior~ Or ~n l.nsulatioll-openlng notch, preferably in a U-shapecl Ghannel, ~or openlrlr the insulatlon and contacting a concluctor wi-th a w~pirlg action ~he notch lncludes an enlarged conductor wlping sur~ace, a smooth lead-in sur~ace3 and a portion which de~lnes a change of directlon between the lead-in surface and the wiplrlg surface. Advantageously, the notch may be formed by press-forming a pair of ln~ardly dlrected detents which carry the abc)ve mentloned surfaces~
although a variety of other structures and techniques may be utilized dependlng on dlfferen~ constructlon and applica-tion requlrements.
Other objects, features and advantages of the lnven-tion, its organization, construction and operation wlll be best understood from the following detailed description taken in conjunction with the accompanying drawlng, on whlch:
FIG. 1 1~ a fragmentary perspective view ~ ~n electrical connector constructed in accordance with the present invention;
FIG. 2 is an enlarged perspective v-lew ~ a por-tlon of a contact termination element constructed in accordance with khe invention;
FIGS. 3, 4 and 5 are sectional views taken sub-stantially along the line II-II of FIG. 1 illustrating an lnsulated stranded conductor at di~ferent posltions during the insertion process;
FIG. 6 ls a fragmentary sectional and isometric view o~ another embodiment of a termination element con-structed in accordance with the present invention;
FIG. 7 is a fragmentary perspective view o~another embodlment of a termination element constructed in accordance with the invention;
.-,' ~1~7~W7 I~IG. c:3.Ls a i:~r~agmellt~lry sec~J.onal pcrs~ectlve v;lew o~` s~lll arlother em~ocllmt,~rlt o~' a term;lrl~tion elemer-lt con-structed in accordarlce wlth tht? irlve~n);lon;
FIG. 9 is a ~'ragmentary sectional perspectlve vlew ~ stlll another embod~ment ~r a termination element construct~d ln accordance wlth l;he ;invention;
FIG. 10 is a ;eragmentary sectional perspect-lve view of yet another embodiment of a terminatlon element constructed in accordance with the invent-lon;
FIG. 11 ls a sectional view taken su~stantiall~
along khe llne XI-~I o~ FIG. 10;
. 12 i8 a per~pective view o~' another embo~i-~ent o~ a termination element of an electrical contack constructed ln accordance with the prlnclples of the present invention;
FIG. 13 is an enlarged sectional v~ew o~ a conkack terminal element supported between barrier walls o~ a con-nector shown before conductor insertion;
FIG. 1~ is an enlarged seckional view slmilar to FIG. 13, illustratlng the terminal element and conductor a~ter insertion;
FIG. 15 is a fragmentary perspectlve view of the : intermediate and actlve elemenks showlng the folded con-structlon ln greater detall;
FIG. 16 is a sectional perspective view illus-trating a folded end o~ the intermediate element as viewed ln the dlrectlon XVI-XVI ln FIG. 15; and FIG. 17 is a sectionàl view taken along the line XVII-XVII o~ FIG. 16 illustrating the provision o~ support legs.
At the outset, one will appreciate that the appar-atus illustrated in FlG. 1, with the exception of the in-ventive leatures disclosed herein, is substantially khe ;ame con~'.L~ruratlorl o~ I(r. 3 oL' ~he a~or(~ment:l.orle(l U. S.
Patent 3,~67,oo5. It ~.s read:Lly apparerlt ~rom F:~G. 3 of that pa~en~, and ~rom the ln~tant FIG. 1, t'rlat the general constructJ.on of arl electrical connect,or unlt accordin~ to th0 present invention, ls generally the same as disclosed ln FIGS. 1, 2 and 3 o~ U. S. Patenk 3,867,oo5. It ls there-fore readily apparent that the plurality o~ conductors and contacts Or an electrical connector accordlng to the Hoppe patent ls also envisloned for an electrical connector which includes the features of' the present lnventlon.
Referring to FIGS. 1 and 2, the baslc construction of an electrical connector ls lllustrated at 10 as comprls-ing a dlelectric contact mount 12 whlch is lllustrated in the ~orm of a plug unit which is adapted ~or connection to a mating complementary receptacle un-lt (not shown). The plug unit comprises the contact mount 12 which is constructed of` molded dielectric material, such as "DAP" Nylon, or Polyester and is designed to have a pluralit~ o~ spaced barriers 14 which define a plurality o~ contact mounting passages 16. Each o~ the barriers 14 lncludes an extended portion 18 whlch de~ines strain relie~ passages 20. Each of the strain relie~ passages 20 includes an entrance de~in~d by a pair of obllque surfaces 22 and 24.
Each of the contact passages 16 includes a contact 26 mounted therein. Each o~ the contacts 26 includes an active contact element 28, here illustrated as having a hook-shaped reentrant portion 29 as in the aforementioned U. S. Patent 3,867,oo5. The active portion could, however, have any desirable shape. The contact 26 also includes a termination contact element 30 and an intermediate contact element or portion connecting the active and te~mination elements, the intermediate portion to be described in detail below.
I!~aC~I t~-!rm;ln~lt;:lo~ rnerlt comprise; a pa-lr (j~ gen~
~rally parallel slclewa:lls 32 and 34 which extend Konerally perpendiclllclr to a bot-tom wall 36 to f'orm an open ~-shaped configuratiorl .
In the~terminat:Lc)rl contact element 30 illustrated in FIGS. 1 and 2, the s;Ldewal:ls 32 and 34 have been di.mpled to provide inwardly ~irected detents 38 whlch ~ef~-ine a channel constrictlon or notch in whlch the constrlcticJn elements are in an interference relatlonship with at least the insulation Or an insulated conductor to be received -ln the channel. Although the notch i8 illustrated as co~-prising a pair of' opposed inwardly directed detents faclng each o~her, the constrictlon may also comprise a palr of lnwardly directed detents which are of~set longitudinally ~ith respect to each other along the terminatlon contact element.
Eaeh o~ the detents 38 includes a pair of inwardly dlrected portions 40 which respectively ~oin the respectlve sidewall and which ~oin together in an enlarged sur~ace 42 which constitutes a wiping sur~ace ~or an exposed conductor, whether the conductor is solld or stranded. Each detent 38 also comprlses a surface 44 which is continuous w-lth the portions 40 and 42 back to the outer edge of the re-spective sldewall. ~he surface 44 is particularly charac-terized as a smooth surface, at least in the area immedl-ately adjaoent the wiping surface 42 and is further char-acterlzed as developing into the wiplng~surface 42 with a gradual change of direction.
In the construction illustrated in FIG. 2, at least one o~ a plurality of channel walls 32/ 34 and 36 af~ord support against insertlon ~orces ~or the detent.
As illustrated, surface 44 ls supported against insertion ~orces in the direction of insertion by first support m~ r~ r~e~cir~ t(~ / hokl;~)rrl wa ~ ,r.~t~ cl)rlrlec~
-to c1eter1t wal:L l~o. ';lcl~ wa:Ll 32 intel~;rally conrlected to d~t;ent wa~l 40 provlde~ a se~corld ~upport mearls ~'or wiplng surface ll2 agalr1~st i.nsertio~ ~orce~ in a dlrection trans-verse to 1he direction of lnsertion.
A~ lllustrated in ~IGS. 3-5J as an lnsulated con-ductor C is ~orced into the channel~ and thus into at least one notch defined by a pair of detents, the lnsulation I
is opened to expose the conductor SC' so that the same is subJected ~o a wiping contacting o~ the surfaces 4'2. As the lnsulation 1~ forced open as it passes the smooth and gradual change of' direction surfaces~ as opposed to an actual cuttLng type severing, the ind-Lvidual strands, if a stranded conductor is employed, are exposed to the change of direction defined by the surfaces, but the strands are not sub,ected to snagging and/or severing as would be the case wlth contact elements heretofore employed.
Referring agaln to FIG. 2, as a conductor is forced downwardly lnto a termination contact element to a desired posit~on, the conductor passes another detent type element 50 which is embossed and lanced to include an underlying edge 54 which engages the insulation to retain the conduc-tor within the channel.
A number of insertion tools may be employed in terminating electrical conductors in the termination con-tact elements constructed in accordance with the present invention. Another tool which is suitable for utilization with the present invention is illustrated, in part, in FIG. l as comprising an insertion blade 58 havi.ng a plur-ality of insertion portions 60, 62 and 64 which are to bepositioned agalnst a conductor at respectiue locations on each side of an insulation notch. The blade 58 includes narrow portions 66 and 68 which may be ~ormed b~ opposed a:~:lgrled W.l.t:: t;h~e llo i;C~ Lorm~d ~y the deteilt;~ 3~3. ~n ad(lit:i~r~11 tile t~ ncly compr:L~e an .lddit:1Oncll portion (not shown) for ~re~3~:irlg 1;he corlc11lc~or ln~o the stra-l.n rellef ge1lera~:1.y def:1ned by the~ passageway 20.
Because o~ the cles:lrabillty ~o use h:Lgh tenslIe strength materia:lsJ and lnasmuch as such materials lnvolve difEicultie~ in forrning reverse bends and the llke, and as it is highly desirable to use such materlals for ex-tended contact llfe, the present inventlon utllizes aunique contact structure which -ls adaptable eor high ten-sile strength materials and mo1lntlng of` the contacts within a contact mount. This structure comprlses a flap or ex-tension of a portlon of the sldewall 34 which is bent at 90 with respect thereto toward the sidewall 32 and a tab 56 on the sidewall 32 whlch is bent in the opposlte direction to overlie and lock the member 57. This ~orms a stable box-shaped structure at the end o~ the termina-tion contact element which is recelved in a complementary box-shaped portion Or khe passage 16 in the connector mount 12. The member 57 carries the active contact element 28 as a forwardly directed (ln the sense of' connector directions) portions thereof.
In some manufacturing processes, and in the case of different applications, it may be more advisable and ad-vantageous to form the notch defining structures b~ differ-ent processes than the aforementioned detenting process by press-forming the side-walls of the termination contact element, or by press-forming the detents ln a different conflguration. Inasmuch as each of the detents is, in effect, an lnternal wall within the channel, the detents are also hereinafter referred to as inner walls which may have individual wall portions or wall sections.
_g _ ~ r~ (,o ~ t~t ~ , t;ll~ 3~m(~ ~r~no~a~.
sh~e f.`or cl, det,ollt~ :Ia ~ Lust;rLIl;e(il as -1; sh~wn :In Li'I(,TS, 1 ancl 2. In E~ T. ~i, hOWeVeI', eactl o~ det~rlts 78 c om-pr.ises a palr oI~ inwclrd:Iy dixected walls 80 ~lnd ~2 whlch conv~rge in a rounde~ surface B4 cln(l which are ~vined by an obll~ue ~urf'clce ~6 haTIlrlg a smooth port:Lon adJacent the surCace 8LI. The walls and surfaces 80-86 are formed ln a separate process as a cup-sh,lped struc~ure wh:Lch is welded around ttle p~rlphery, as at 88, to the respective sidewall 10 72 which extends from a bottom wa].l 76 parallel to a com-plementary sidewall 74 of a t,ernlination contact element 70.
Referring to FIG. 7~ a termination contact ele-ment 110 is brie.~ly illustrated as comprising a sidewall 112 (the other sldewall not being shown) which extends generally normal to a bottom wall 11~. An inner wall 116 is illustrated as comprising a pair of inwardly directed walls 118 and 120 having a bottom edge 122 above the bottom wall 114 and which are connected by a generally wide wiplng sur~ace wall 124. An additlonal wall 126, characterized by smooth portion ad~acent the surface 124, joins the walls 118, 120 and 124 with the free edge of the sidewall 112.
Referring to FIG. 8, a termination contact element 90 is illustrated as having an lnner wall 96, formed as a detent, including a pair of inwardly directed walls 98 and 100 extending from the sidewall 92 which, in'turn, projects from a bottom wall 94. The contact element 90 may also include another sidewall as in FIGS. 1-5.
A smooth slanted surface 106 ad~acent the surface 104 is carr-led,by a mem~er 108 o~ thin conductive sheet metal which is connected to and bent at an angle with re-spect to the surface 104 with its smooth ma~or surface extending as a cover a~d guide over walls 98 and 100. An aperture 102 has been provided at the junction of the .
G ~ .rl (.~ J r) tJ l~ orn ~ 9l~ ~) f',~ Lt;~ 3 ~'o~rnin~ o~' the c1el,erll; ~y a ~)resslllg process su t;hal, lanc:in~ or an abrupt swedglrl~;; is rlot neces~3al~y at that poirlt;.
~ el~errirlg t~ l?IG. 9) another illustrat,ive embodi-rnent o~ a termlrla~lon con~ac-t element :ls shown at 130 as comprislng at least one sldewall 132 wh-ich pro~ects frorn a bottom wal:L :l36. Of course, a slmllar sidewaLl may ex~
tend from the bottom wall 136 in complementary opposTtion to the sidewall 132. The channel of' the te~lination con-10 tact element includes an lnner wal:L 138 whlch ls formed outof bent substantia].ly 90 f'rom the sidewall 132, the bend-ing being facllitated by an aperture 134 at the junct,ion of the sldewall 132 and the bottom wall 136. The -lnner wall 138 comprises a sidewall portion 140 having an edge 142J
substantlally the thickness of the sldewa:Ll 132 which forms the wiplng surface f'or the conductor. The sidewall portion 140 includes an extended portion 146 which is folded over in a smooth inwardly and downwardly directed fold 144 to define the smooth entrance of the notch~ the junction of the edge surface 142 and the rounded surface 144 deflnlng the change of~ dlrectlon mentloned in respect of the above embodiments.
Referrlng to FIGS. 10 and 11, a terminatlon con-tact element 150 -ls lllustrated as comprlsing a sidewall 152 whlch extends from a bottom wall 154. Again, a complemen-tary opposed sidewall may be provided. 'rhe sidewall 152 has been relieved by an aperture at 164 to facilltate the forming of a dimple ln the production of an inner wall 156 which includes a palr of convergently inwardly directed surfaces 158 and 160 whlch are ~o~ned at a rounded surface 162 which constitutes the conductor wiplng surface. In thls embodiment of the invention the press forming o~ the inner wall occurs more closely adjacent the free edge of 7~7 t~le sl(lewa~ 7,~ Irl F:L(~. ~; sc-, ~ha~; ~he upper edge :l66 of the siclewal:l. 152 is turne(l outwardly and forms a V~shaped notch.
The space hetween ~he V-shaped notch and the Junctlon of`
the suraces 158, 160 and 1~2 therewlth constltutes a smooth surface 168 rOr guldLng the conductor into the notch and preventlng snagg-lng o;~ the individual st~.nds of a stranded conductor as the notch effects opening of thè
insulation. The edges of the V ma~ be colned i~ neces-sar~, to prevent snagging, Referring to FIG. 12, a "channel" without sidewalls is lllustrated, although it is readily apparent that ~ide-walls could be provlded. In FIG. 12, a flat piece of sheet metal is folded three times to form each notch. A "channel"
comprlses a bottom wall 172 hav-lng a palr of notch-de~ining pro~ections extending therefrom, due to the folding process.
Each o~ these pro~ections comprises a pair of coextensive wall sections 17~ and 176 which are ~oined by a rounded, smooth and inwardly obliquely dlrected surface 178. The bottom wall 172 has an aperture therethrough having side-walls 180 which form the wiping surface or surfaces for the exposed conductor.
Re~erring to FIGS. 13 and 14, a more detailed showing of the relationships between the terminal element and the conductor insulation and core are illustrated. As an example) the ~ollowing values are prov-lded ror a clearer understanding of the invention.
D-lameter . ~ . . . . . . . . . . 0.045 Diameter SC. . . . . . . . . . . 0.020 0.015 Notch Width a. O . . . . . . . . 0.009 Channel Inside Width b . . . . . . . . . 0.038 Channel OUtside Width c . . . . . . . . . 0.051 0.049 Barrier-Barrier Distance d . . . . . . . 0.054 ~ rOr11 t;hC d:l!(lell'l;t.OILS ~:';;LV(UI cli~OVC~ Ls appar~rll;
tilat al.l;hOUg,h l;hl' .LiiaU.La~.orL :L3 ~l~)pro~iml~.L;y the sarne d-iamet;~r a~; t;h~ :Lnsttle oL~ the ch~nil~l, th~ conductor d~am~ter i~ much l~lrger tharl the w:klth of the notch. There-for~) as the insula1,ed conductor -l.s pre~ssed into the charl-nel, even assumlng that thc corlductor :ls centered~ a stran-ded core undergoes a cross-sectional di3kortlon due to displacement of the indiVidual strands during insertlon.
This is ll.lustrated in ~'IG. 14. A~sol as pressure is ap-plied to the insulation by an lnsertion tool, the lnsulatlon undergoes dlstortlon and is moved axially of the core and outwardly o~ the channel. It ls dirficult to tell exactly where any individual strand may initlally contact the sur-~ace 44 which leads into the notch. Theref`ore, a smooth surface 44 with a gradual change o~ direcklon to the wip-lng surface is pref`erred to prevent snagglng o~ the indlvidual strands. With larger strands and solld conductors the change of direction can be more abrupt -Ln that the possibility of snagging decreases wlth increasing conductor diameter.
Ref`err~ng again to the dimensions given above, it is readily apparent that any transverse deflection Or the sidewalls 32 and 34 is at a m-lnimum because o~ the dlf~er-ence between the outside channel dimension and the distance between the barriers, for example~ 0.003 inches. The ter-minal element is there~ore well supported and does not open up to any extent to receive the conductor thus insuring good mechanical connect:Lon and good wiping electrical connection.
Rererrlng to FIGS. 15~17, additional details of the box-shaped structure o~ the intermediate element are 3 illustrated. It should be noted that the member 57 includes an embossed detent 184 ~or receiving the tab 56 such that the outer surfaces of the member 57 and the tab 56 are co-planer~ which facilitates insertion of the terminal ends o~
1~7~7 the contacts into the dlelectr:Lc support 12.
One of the slclewalls, the wall 34 ;Ln FIG. 16,also carries a member whlch is folded at 90 toward the opposlte sidewall as ano-ther feature of the box-like structure.
It is sometimes necessary to provide supporting feet for the intermediate element of a cont,act. Refer~-lng to FIG. 17, the bottom wall 36 of the channel may be cuk such as at 186 and 188 to provide a pair of bottom wall sections l90 and 192 which may be folded downwardly to pro-vide supporting feet.
In summary, therefore~ we have dieclosed an in~u-lation-plercing or opening aontact for use in an electrical connector for connection to an insulated conductor, in par-ticular an insulated stranded conductor. The contack, in some embodiments, includes an open channel for receiving the insulated conductor normal to its axis, the channel lnclud-ing a bottom wall and a pair of spaced s~dewalls extending generally parallel to each other from the bottom wall. The channel includes at least one pair of interior walls, ~hich may be constructed of press-formed detents, and which extend inwardly of the channel from respective sidewalls. Each of the interior walls comprises an oblique surface dlrected away from the respeckive sidewall and toward the bottom wall, a conductor wiping surface extending generally in the direction of conductor insertion, and an insulation opening portion joining the oblique and wiping surfaces and defining a change of direction be~ween such surfaces. A smooth portion is providecl on the oblique surface immedlately adja-cent the insulation opening portion advantageously prevents snagging when stranded type conductors are being terminated.
For larger strands, a more abrupt change of direction may be employed; however~ a smooth, gradual change is preferred for conductors in the area of 24-28 gauge.
--1~-St;ate~3 ~.rlother wayJ tt)e lnventl.o~ a ~peclf'l.c lmprovement ror ~lectrical:].y t~ni~a~lrlg an in~ulated stranded corl~uctor, as wcll a3 an insulated solid conduct,or, in an insulated p~ercing contact Or the t~Jpe ln which an lnsulated conductor 1~ pressed normal to its axis into ~n insulated-piercirlg notch wh:Lch has an entrance and a con-ductor wip:lng sur:~ace extendlng transversely of the axls of the conductor. The improvement more speclfically com-prises a smooth ~ur.~ace :immediately adJacent the entrance o~ the notch and extendlng obllque to the notch and a ~unction at the notch enkrance between the smooth surface and the wiplng sur~ace o~ the notch which defines a change of direction between the wiplng surface and the notch entrance, so that, in the case of stranded conductors, exposed strands are not sub~ected to snagging and/or sever-ing by sharp pro~ections or a sharp edge along the guide and lnsulation~opening paths.
Also, according to the invention, an insulation-piercing or -opening contact ~or an electrical connector has been disclosed as comprising a channel for receiving the insulated conductor in a direction normal to its longi-tudinal axis) and notch means in the channel defining a constriction havlng an interference relationship with the insulation of the insulated conductor. The notch means defines conductor guiding, insulation opening and conductor ^-wiping zones and includes a conductor wiping surface which extends generally in the direction of conductor insertion, a conductor guiding surface extending oblique to the wiping surface, and an insulation opening portion connecting and defining a change of direction between the guiding and wiplng surfaces, the guiding surface including a smooth zone immediately adjacent the insulation opening portlon which advantageously serves to prevent snagging of the i.ncl.lvldual ~trarlds of' an :i.nsulated strarlded corlductor.
Accord:in~; ~,o ~;he lnvetlt.l.orl~ an electrical connector unit has also beerl dlsclosed which uti:llzes a plurality o~
contact members rnounted ln ;Lndividual contact mountirlg passages of a con~ack mount of` dielectric materlal. Each of the contact members may advantageously be formed f'rom high tenslle strength sheet metal and comprises an act:Lve contact elementg a terminal contact element and an inter-mediate contact element connecting l;he active and terminal contact elements. The termi~lal element is in the shape of an elongate U-shaped channel w:Lth a box-like structure at its ~unctlon with the intermediate contact element, the intermediate contact element carrying the actlve contact element.
Although we have described our invention by refer-ence to a partLcular illustrative embodiment thereof~ many changes and modifications o~ the invention may become apparent to those skilled in the art without departing from the spirlt and scope of the lnvention. We therefore intend to include within the patent warranted hereon all such changes and modlfications as may reasonably and proper-ly be included within the scope of our contributlon to the art.
Claims (12)
1, An insulation-opening contact of the type wherein an insulated conductor is pressed into a notch which opens the insulation and provides a wiping contact surface portion for the conductor, comprising: a thin sheet metal structure forming an open channel for receiving an insulated conductor inserted perpen-dicular to the axis of said conductor, said channel including a bottom wall and a pair of spaced sidewalls extending generally parallel to each other from said bottom wall, at least one pair of detents, extending inwardly in the channel, each detent having vertical walls, each detent of said pair being opposite the other, each detent comprising a continuous and oblique surface directed towards the bottom wall and having rounded change in direction which surface forms an entity with an upper portion of the vertical walls of each detent and which is continued by the junction of the vertical walls to form the wiping contact surface, the con-tinuous and oblique surface containing a guiding surface and an insulation-opening surface which forms a curved transition surface to the wiping contact surface.
2. The contact according to claim 1 wherein the detents are attached to opposing surfaces of the sidewalls.
3. The contact according to claim 2 wherein the detents are welded to the inside surfaces of the sidewalls.
4. The contact according to claim 1 wherein each of the detents has a substantially triangular-shaped horizontal cross section with two vertical walls, one side of each vertical wall attached to the inside surface of the sidewall and the wiping con-tact surface formed from a curved corner of each triangular-shaped horizontal cross section.
5. The contact according to claim 1 and further com-prising conductor retention means including at least one projection extending from a respective sidewall and defining a restriction in said channel, said projection including an underlying ledge to engage the insulation and retch the conductor after the same has been inserted past said ledge,
6. The contact according to claim 1 and further com-prising an active element and an intermediate element connecting said channel and said active element, said intermediate element comprising a member carrying said active element and extending from one of said sidewalls toward the other sidewall to form a box-shaped end for said channel, and a tab extending prom the other sidewall towards said one sidewall to overlie said member.
7. The contact according to claim 1 wherein each of the de-tents has a substantially rectangular-shaped horizontal cross section with three vertical walls.
8. The contact according to claim 1 wherein each of the detents has a substantially triangular-shaped horizontal cross section and is pressed from each of the pair of spaced sidewalls.
9. The contact according to claim 8 wherein the contin-uous and oblique surface is a flap of sheet metal, and a bend in the flap forms the curved transition surface to the wiping contact surface.
10. The contact according to claim 8 including a V-shaped cutout in the oblique surface extending from a plane in line with the sidewall and forming a continuous edge with the edge of the sidewall and facing away from the cutout.
11. The contact according to claim 1 wherein each of the detents include a bent cup-shaped portion extending inwardly from each of the pair of spaced sidewalls, each of the cup-shaped portions including a continuous and oblique surface forming a guiding surface directed away from the sidewall and towards the bottom wall extending into the curved transition surface forming an insulation-opening surface which joins a wiping contact surface formed by an opposing surface of the cup-shaped portion, and which extends towards the bottom wall, the guiding surface extending substantially parallel to the spaced sidewall.
12. The contact according to claim 11 wherein the oblique surface, transition surface and wiping contact surface provide a continuous smooth surface on the inner surface of each one of the pair of spaced sidewalls.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/606,121 US4373769A (en) | 1975-08-20 | 1975-08-20 | Electrical connector including insulation-opening contact |
| US606,121 | 1975-08-20 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1117197A true CA1117197A (en) | 1982-01-26 |
Family
ID=24426628
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000259357A Expired CA1117197A (en) | 1975-08-20 | 1976-08-18 | Electrical connector including insulation-opening contact |
Country Status (9)
| Country | Link |
|---|---|
| US (1) | US4373769A (en) |
| JP (1) | JPS5225282A (en) |
| AU (1) | AU509783B2 (en) |
| BR (1) | BR7605255A (en) |
| CA (1) | CA1117197A (en) |
| DE (1) | DE2637378A1 (en) |
| FR (1) | FR2321783A1 (en) |
| GB (1) | GB1561989A (en) |
| IN (1) | IN146960B (en) |
Families Citing this family (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IL54479A0 (en) * | 1977-04-18 | 1978-07-31 | Bunker Ramo | Electrical connectors |
| JPS5733572Y2 (en) * | 1977-11-22 | 1982-07-23 | ||
| FR2415374A1 (en) * | 1978-01-23 | 1979-08-17 | Nozick Jacques | Connector electrode with automatic insulation stripper - has U=shaped cross=section formed from cut and pressed single metal strip |
| FR2436510A2 (en) * | 1978-01-23 | 1980-04-11 | Nozick Jacques | Electrical connector for cable end - has self-stripping insulating sheath with contact element of phosphor bronze with attachment to hold wire firmly against movement |
| US4209217A (en) | 1978-10-26 | 1980-06-24 | Thomas & Betts Corporation | Housing for removable mounting on printed circuit board |
| DE3115434A1 (en) * | 1981-04-16 | 1982-11-11 | Grote & Hartmann Gmbh & Co Kg, 5600 Wuppertal | "TERMINAL CONTACT" |
| US4662699A (en) * | 1981-11-13 | 1987-05-05 | Magnetic Controls Co. | Electrical connector module |
| US4699441A (en) * | 1984-09-14 | 1987-10-13 | Amp Incorporated | Electrical connector for stranded wires |
| US4648679A (en) * | 1985-11-15 | 1987-03-10 | Allied Corporation | Connector assembly for mass termination |
| GB8817783D0 (en) * | 1988-07-26 | 1988-09-01 | Amp Gmbh | Electrical contact member |
| DE3912273A1 (en) * | 1989-04-14 | 1990-10-18 | Minnesota Mining & Mfg | CONNECTOR FOR INSULATED LADDERS |
| US5344336A (en) * | 1993-06-04 | 1994-09-06 | Molex Incorporated | Insulation displacement electrical terminal |
| US6012942A (en) * | 1995-12-29 | 2000-01-11 | Volstorf; James R. | Insulation displacement contact dimple and method of manufacture |
| DE19635872B4 (en) * | 1996-09-04 | 2004-05-19 | Langbein, Peter, Prof. Dr.-Ing.habil. | Electrical connector |
| JPH10223268A (en) * | 1997-02-07 | 1998-08-21 | Yazaki Corp | Pressure contact terminal |
| JP3895466B2 (en) * | 1998-05-18 | 2007-03-22 | 本田技研工業株式会社 | IDC type connector |
| JP2002158045A (en) * | 2000-11-21 | 2002-05-31 | Auto Network Gijutsu Kenkyusho:Kk | Pressure welding blade applicable for very thin wire |
Family Cites Families (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR377374A (en) * | 1907-05-03 | 1907-09-05 | Burton Stearns Philbrook | Improved method and apparatus for the reproduction, in natural colors, of images or photographs |
| NL67298C (en) * | ||||
| US3162501A (en) * | 1960-01-21 | 1964-12-22 | Amp Inc | Electrical connector |
| FR1523832A (en) * | 1966-06-01 | 1968-05-03 | Amp Inc | Moisture-proof electrical connector |
| DE2022028B1 (en) * | 1970-05-05 | 1971-04-22 | Krone Kg | Detachable electrical clamp connection |
| US3883212A (en) * | 1970-08-17 | 1975-05-13 | Bunker Ramo | Contact for multiple conductor connector |
| US3657682A (en) * | 1970-08-26 | 1972-04-18 | Viking Industries | Electrical connector |
| DE7212035U (en) * | 1972-03-29 | 1972-06-29 | Siemens Ag | Clamping element for the stripping-free connection of electrical conductors |
| US3717841A (en) * | 1972-05-18 | 1973-02-20 | Berg Electronics Inc | Socket terminal |
| AU5574573A (en) * | 1972-05-30 | 1974-11-21 | Amp Inc | Electrical contact elements and connectors electrical contact elements and connectors |
| US3867005A (en) * | 1972-09-14 | 1975-02-18 | Bunker Ramo | Insulation-piercing contact member and electrical connector |
| US3926498A (en) * | 1972-09-14 | 1975-12-16 | Bunker Ramo | Electrical connector and insulation-piercing contact member |
| CA1009827A (en) * | 1973-06-14 | 1977-05-10 | Istvan Mathe | Tool and adapter for electrical connector unit using insulation piercing contacts |
| CA983597A (en) * | 1973-09-10 | 1976-02-10 | Paul P. Hoppe (Jr.) | Insulation-piercing contact member and electrical connector |
| GB1490197A (en) * | 1974-02-19 | 1977-10-26 | Trw Inc | Solderless termination system |
| US3902154A (en) * | 1974-02-19 | 1975-08-26 | Trw Inc | Strain relief |
-
1975
- 1975-08-20 US US05/606,121 patent/US4373769A/en not_active Expired - Lifetime
-
1976
- 1976-07-28 IN IN1345/CAL/76A patent/IN146960B/en unknown
- 1976-07-29 AU AU16374/76A patent/AU509783B2/en not_active Expired
- 1976-08-09 GB GB33123/76A patent/GB1561989A/en not_active Expired
- 1976-08-11 BR BR7605255A patent/BR7605255A/en unknown
- 1976-08-16 FR FR7624861A patent/FR2321783A1/en active Granted
- 1976-08-18 CA CA000259357A patent/CA1117197A/en not_active Expired
- 1976-08-19 JP JP51098254A patent/JPS5225282A/en active Pending
- 1976-08-19 DE DE19762637378 patent/DE2637378A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| FR2321783B1 (en) | 1982-04-09 |
| DE2637378C2 (en) | 1987-02-05 |
| AU509783B2 (en) | 1980-05-22 |
| FR2321783A1 (en) | 1977-03-18 |
| AU1637476A (en) | 1978-02-02 |
| DE2637378A1 (en) | 1977-03-03 |
| JPS5225282A (en) | 1977-02-25 |
| BR7605255A (en) | 1977-08-09 |
| GB1561989A (en) | 1980-03-05 |
| IN146960B (en) | 1979-10-20 |
| US4373769A (en) | 1983-02-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1117197A (en) | Electrical connector including insulation-opening contact | |
| EP0021731B1 (en) | Electrical contact member and connector including such contact members | |
| US5338220A (en) | Electrical connector housing assembly and an electrical terminal therefor | |
| AU679270B2 (en) | Electrical connectors | |
| EP0279508B1 (en) | Electrical terminal | |
| JPS5936386B2 (en) | electrical terminals | |
| EP0372767B1 (en) | Miniature insulation displacement electrical contact | |
| CA1082325A (en) | Electrical connectors with terminals having wire- receiving portions for inserting wires | |
| JPS581514B2 (en) | electrical contact device | |
| EP0664575B1 (en) | Electrical connector with slotted beam contact | |
| US4767353A (en) | Two part connector housings in strip form | |
| EP0007194B1 (en) | Wire insulation piercing electrical connector | |
| WO1986007200A1 (en) | Heavy current electrical termination means | |
| US4264118A (en) | Insulation-pierce and crimp termination and method for effecting same | |
| EP0195784B1 (en) | Electrical connector for stranded wires | |
| CA1195398A (en) | Terminal for solderless contact | |
| EP0722197B1 (en) | Insulation displacement contact for multiple wire sizes | |
| AU723780B2 (en) | Connection device for at least two sheathed conductive wires | |
| EP0128649B1 (en) | Insulation-shearing electrical terminal | |
| US4414740A (en) | Insulation-pierce and crimp termination tool | |
| KR0138656B1 (en) | Electrical terminal and method of terminating a wire to such terminal | |
| US5014535A (en) | Apparatus for forming embossments on electrical contact terminals | |
| CA1115371A (en) | Connector including a contact for forming a crimped insulation-piercing electrical connection | |
| EP0856912B1 (en) | Insulation displacement electrical connector for multiple inline conductors | |
| CA1229670A (en) | Insulation displacing terminal with cantilever spring contact members |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |